Persistent Asymptomatic Isolated Microscopic Hematuria in Adolescents is not Associated With an Increased Risk for Early Onset Urinary Tract Cancer.

Objective: To elucidate the association between adolescent microscopic hematuria and early onset urothelial carcinoma and renal cell carcinoma.

Methods: Nationwide, population-based, retrospective cohort study using medical data of 970,366 adolescents aged 16 through 19 years (58.6% male) examined for fitness for military service between 1980 and 1997. Diagnoses of persistent isolated microscopic hematuria were given after thorough work up process excluding any other renal abnormalities. Incident cases of urothelial carcinoma and renal cell carcinoma diagnosed during the years of 1982-2012 were retrieved from the Israeli National Cancer Registry. Cox proportional hazards models were used to estimate the hazard ratio (HR) separately for urothelial carcinoma and renal cell carcinoma.

Results: During a cumulative follow-up of 22,115,629 person-years (median follow-up, 22.8), persistent isolated microscopic hematuria was diagnosed among 5509 (0.6%) adolescents. Urothelial carcinoma and renal cell carcinoma developed in 332 (3 among those with persistent isolated microscopic hematuria) and 292 (2) individuals, respectively. The adjusted HR for incident urothelial carcinoma among adolescents with isolated microscopic hematuria was 1.17 (95% CI, 0.38-3.66) and the adjusted HR for renal cell carcinoma was 1.02 (95% CI, 0.25-4.12).

Conclusion: Persistent asymptomatic isolated microscopic hematuria at adolescence was not associated with increased risk for urothelial carcinoma nor renal cell carcinoma.